Methods for producing dried pesticide compositions

Abstract

Disclosed are compositions and methods related to powder and granular emulsifiable concentrate pesticide formulations. As disclosed, emulsions from non-aqueous based liquid or solvent soluble pesticide actives may be prepared using a high purity, high molecular weight sulfonated lignin as the emulsion stabilizer. The resulting emulsions may then be dried to obtain a powder or granular emulsion concentrate where the high molecular weight sulfonated lignin acts as a solid matrix for the pesticide active. The powder or granular emulsifiable concentrate formulations thus formed have high loading rates, good storage properties and are easily reconstituted when added to water.

1. A method for preparing a dried pesticide composition, the method comprising:
 (a) preparing an aqueous lignosulfonate solution by dissolving a lignosulfonate material in water or an aqueous solution, wherein the lignosulfonate material comprises at least 90% (w/w) softwood lignosulfonate and the softwood lignosulfonate has an average molecular weight of 40 kDa to 100 kDa; 
 (b) combining the aqueous lignosulfonate solution with a hydrophobic liquid and forming an emulsion, wherein the hydrophobic liquid comprises a pesticide active; and 
 (c) drying the emulsion to remove the water and to form the dried pesticide composition in a granular form. 
 
     
     
       2. The method of  claim 1 , wherein forming the emulsion comprises subjecting the combined aqueous lignosulfonate solution and hydrophobic liquid to mechanical shear. 
     
     
       3. The method of  claim 1 , wherein the hydrophobic liquid comprises a pesticide compound dissolved in an organic solvent. 
     
     
       4. The method of  claim 1 , wherein the emulsion comprises hydrophobic droplets or particles having a mean volume diameter of less than about 5 microns. 
     
     
       5. The method of  claim 1 , wherein the dried pesticide composition is a granular composition comprising granules having an average diameter of about 1 mm to about 8 mm. 
     
     
       6. The method of  claim 1 , wherein the dried pesticide composition is a powder composition comprising particles having an average diameter of less than 1 mm. 
     
     
       7. The method of  claim 1 , further comprising granulating the dried pesticide composition to form a granular composition comprising granules having an average particle diameter of about 1 mm to about 8 mm. 
     
     
       8. The method of  claim 1 , further comprising:
 (d) combining the dried pesticide composition with water or a second aqueous solution to form a second emulsion. 
 
     
     
       9. The method of  claim 8 , wherein the second emulsion comprises hydrophobic droplets or particles having a mean volume diameter of less than about 5 microns. 
     
     
       10. The method of  claim 1 , wherein the lignosulfonate material comprises at least about 95% (w/w) softwood lignosulfonate. 
     
     
       11. The method of  claim 1 , wherein the softwood lignosulfonate has an average molecular weight of about 40 kDa to about 60 kDa. 
     
     
       12. The method of  claim 1 , wherein the emulsion comprises about 15% (w/w) softwood lignosulfonate to about 35% (w/w) softwood lignosulfonate. 
     
     
       13. The method of  claim 1 , wherein the pesticide active comprises an agent selected from the group consisting of a thiocarbamate, a haloacetanilide, a nitroaniline, an organophosphate, a pyrethroid, a strobilurin, and mixtures thereof. 
     
     
       14. The method of  claim 13 , wherein the thiocarbamate is selected from the group consisting of ethyl dipropylthiocarbamate (EPIC); ethyl N,N-diisobutylthiocarbamate (butylate); S-ethyl N-ethylthiocyclohexanecarbamate (cycloate); S-Ethyl N,N-hexamethylenethiocarbamate (molinate); S-propyl dipropylthiocarbamate (vernolate); and mixtures thereof. 
     
     
       15. The method of  claim 13 , wherein the haloacetanilide is selected from the group consisting of 2-Chloro-2′-methyl-6-ethyl-N-ethoxymethylacetanilide (acetocholor); 2-Ethyl-6-methyl-1-N-(2-methoxy-1-methylethyl)chloroacetanilide (metolachlor); 2-Chloro-2′,6′-diethyl-N-(methoxymethyl)acetanilide (alachlor); 2′,6′-Diethyl-N-butoxymethyl-2-chloroacetanilide (butachlor); 2-Chloro-N-isopropylacetanilide (propachlor); and mixtures thereof. 
     
     
       16. The method of  claim 13 , wherein the nitroaniline is selected from the group consisting of 2,6-Dinitro-N,N-dipropyl-4-trifluoromethylaniline (trifluralin); 2,6-Dichloro-4-nitroaniline (dicloran); and mixtures thereof. 
     
     
       17. The method of  claim 13 , wherein the organophosphate is selected from the group consisting of Diethyl 4-nitrophenyl phosphorothionate (parathion); S-(1,2-Di(ethoxycarbonyl)ethyl) dimethyl phosphorothiolothionate (malathion); O-Ethyl S-phenyl ethylphosphonothiolothionate (fonofos); and mixtures thereof. 
     
     
       18. The method of  claim 13 , wherein the pyrethroid is selected from the group consisting of permethrin, lambda-cyhalothrin, deltamethrin, tralomethrin, cypermethrin, tefluthrin, and mixtures thereof. 
     
     
       19. The method of  claim 13 , wherein the strobilurin is selected from the group consisting of azoxystrobin, kresoxim-methyl, picoxystrobin, fluoxastrobin, oryzastrobin, dimoxystrobin, pyraclostrobin, trifloxystrobin, and mixtures thereof. 
     
     
       20. A method for preparing a granular pesticide composition, the method comprising:
 (a) preparing an aqueous lignosulfonate solution by dissolving a lignosulfonate material in water or an aqueous solution, wherein the lignosulfonate material comprises at least 90% (w/w) softwood lignosulfonate having an average molecular weight of about 40 kDa to about 60 kDa; 
 (b) combining the aqueous lignosulfonate solution with a hydrophobic liquid and forming an emulsion, wherein the hydrophobic liquid comprises a pesticide active; and 
 (c) drying and granulating the emulsion to obtain the granular pesticide composition, wherein the granular pesticide composition comprises granules having an average particle diameter of about 1 mm to about 8 mm. 
 
     
     
       21. The method of  claim 20 , wherein forming the emulsion comprises subjecting the combined aqueous lignosulfonate solution and the hydrophobic liquid to mechanical shear. 
     
     
       22. The method of  claim 1 , wherein the emulsion comprises 15-45% (w/w) of the hydrophobic liquid. 
     
     
       23. The method of  claim 20 , wherein the emulsion comprises 15-45% (w/w) of the hydrophobic liquid. 
     
     
       24. The method of  claim 1 , wherein the emulsion comprises 20-40% (w/w) of the hydrophobic liquid. 
     
     
       25. The method of  claim 20 , wherein the emulsion comprises 20-40% (w/w) of the hydrophobic liquid. 
     
     
       26. The method of  claim 1 , wherein the emulsion comprises hydrophobic droplets or particles having a mean volume diameter of less than about 2 microns. 
     
     
       27. The method of  claim 20 , wherein the emulsion comprises hydrophobic droplets or particles having a mean volume diameter of less than 2 microns. 
     
     
       28. The method of  claim 1 , wherein after the dried pesticide composition is combined with water, the dried pesticide composition forms a second emulsion. 
     
     
       29. The method of  claim 28 , wherein the second emulsion comprises hydrophobic droplets or particles having a mean volume diameter of less than 5 microns. 
     
     
       30. The method of  claim 20 , wherein after the granulated pesticide composition is combined with water, the granulated pesticide composition forms a second emulsion. 
     
     
       31. The method of  claim 30 , wherein the second emulsion comprises hydrophobic droplets or particles having a mean volume diameter of less than 5 microns.